refactor: Update Client.run to have a better async I/O usage

[DA-344]

Summary

This PR refactors the Client.run logic to fix problems involving asyncio due to how the library used the loop:

Needs testing

Exception

  File "/home/container/main.py", line 23, in <module>
    bot.run(BOT_TOKEN)

  File "/home/container/.local/lib/python3.11/site-packages/discord/client.py", line 772, in run
    loop.run_forever()

  File "/usr/local/lib/python3.11/asyncio/base_events.py", line 608, in run_forever
    self._run_once()

  File "/usr/local/lib/python3.11/asyncio/base_events.py", line 1936, in _run_once
    handle._run()

  File "/usr/local/lib/python3.11/asyncio/events.py", line 84, in _run
    self._context.run(self._callback, *self._args)

  File "/usr/local/lib/python3.11/asyncio/selector_events.py", line 956, in _read_ready
    self._read_ready_cb()

  File "/usr/local/lib/python3.11/asyncio/selector_events.py", line 988, in _read_ready__get_buffer
    self._protocol.buffer_updated(nbytes)

  File "/usr/local/lib/python3.11/asyncio/sslproto.py", line 439, in buffer_updated
    self._do_handshake()

  File "/usr/local/lib/python3.11/asyncio/sslproto.py", line 560, in _do_handshake
    self._sslobj.do_handshake()

  File "/usr/local/lib/python3.11/ssl.py", line 979, in do_handshake
    self._sslobj.do_handshake()

Information

• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed).
• This PR is not a code change (e.g. documentation, README, typehinting,
  examples, ...).

Checklist

• I have searched the open pull requests for duplicates.
• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why.
• I have updated the changelog to include these changes.

[DA-344]

Applied all the changes Dorukyum requested.

Before merging, I would like some feedback on this discussion message

[Copilot]

Pull Request Overview

This PR refactors the Client.run logic to improve async I/O usage and fix asyncio-related issues that could occur when using the library's event loop handling.

• Replaces asyncio.iscoroutinefunction with inspect.iscoroutinefunction throughout the codebase for better reliability
• Refactors Client.run to use modern asyncio.run instead of manual loop management
• Updates loop handling to be more flexible with None values and better async context management

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
discord/utils.py	Added inspect import and replaced asyncio.iscoroutinefunction
discord/state.py	Updated loop handling to accept None and added dispatch wrapper
discord/http.py	Simplified loop initialization to accept None values
discord/ext/tasks/__init__.py	Major refactor of task loop handling and scheduling logic
discord/ext/commands/core.py	Replaced asyncio.iscoroutinefunction with inspect equivalent
discord/commands/core.py	Replaced asyncio.iscoroutinefunction with inspect equivalent
discord/client.py	Major refactor of Client.run and loop management
discord/bot.py	Replaced asyncio.iscoroutinefunction with inspect equivalent
CHANGELOG.md	Added entry documenting the async I/O fixes

---

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[Soheab]

Can't seem to manually call login + connect:

Error

Traceback (most recent call last):
  File "C:\xxx\pr2645.py", line 19, in <module>
    asyncio.run(main())
    ~~~~~~~~~~~^^^^^^^^
  File "C:xxx\uv\python\cpython-3.14.0-windows-x86_64-none\Lib\asyncio\runners.py", line 204, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "C:\xxx\uv\python\cpython-3.14.0-windows-x86_64-none\Lib\asyncio\runners.py", line 127, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "C:\xxx\uv\python\cpython-3.14.0-windows-x86_64-none\Lib\asyncio\base_events.py", line 719, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "C:\xxx\pr2645.py", line 16, in main
    await client.connect()
  File "xxx\.venv\Lib\site-packages\discord\client.py", line 761, in connect
    self.ws = await asyncio.wait_for(coro, timeout=60.0)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\xxx\uv\python\cpython-3.14.0-windows-x86_64-none\Lib\asyncio\tasks.py", line 488, in wait_for
    return await fut
           ^^^^^^^^^
  File "C:\xxx\.venv\Lib\site-packages\discord\gateway.py", line 348, in from_client
    ws = cls(socket, loop=client.loop)
                          ^^^^^^^^^^^
  File "C:xxx\.venv\Lib\site-packages\discord\client.py", line 369, in loop
    raise RuntimeError("loop is not set")
RuntimeError: loop is not set
Unclosed client session

Code

import asyncio
import discord


client = discord.Client()


@client.event
async def on_ready():
    print(f"We have logged in as {client.user}")


async def main():
    await client.login("xxx")
    await client.connect()


asyncio.run(main())

[Soheab]

ext.tasks seems to be broken and the changes to it aren't in the changelog?

1. This task runs automatically

@tasks.loop(seconds=1)
# @tasks.loop(seconds=1, create_loop=False) # <- default
async def my_background_task():
    print("Background task is running...")
 

# my_background_task.start() <- does nothing
client.run(...)

2. This task does not run

@tasks.loop(seconds=1)
# @tasks.loop(seconds=1, create_loop=False) # <- default
async def my_background_task():
    print("Background task is running...")
 

# optional: my_background_task.start()

3. This task does not run

@tasks.loop(seconds=1, create_loop=True)
async def my_background_task():
    print("Background task is running...")
 

client.run(...)

4. This task does not ran and logs a warning

@tasks.loop(seconds=1, create_loop=True)
async def my_background_task():
    print("Background task is running...")
 

my_background_task.start()
# console:
# Task was destroyed but it is pending!
# task: <Task pending name='pycord-ext-task (0x1f4fb9d3380): my_background_task' coro=<Loop._loop() running at C:\Users\Sohea\OneDrive\Documents\test\pycord\.venv\Lib\site-packages\discord\ext\tasks\__init__.py:213>>
# <sys>:0: RuntimeWarning: coroutine 'Loop._loop' was never awaited

This is all super confusing and so is the doc of the create_loop parameter.

[Paillat-dev]

2. This task does not run

Isn't that the same code as task number one ?

[Soheab]

Isn't that the same code as task number one ?

Yes but without running the bot, which is what I assumed create_loop allowed.

[Paillat-dev]

Added medium prio, this fixes multiple issues and is a much needed cleanup, will check everything out to try and find out more about those loop issues.

[Paillat-dev]

Can't seem to manually call login + connect:

Also got that same issue.

@DA-344 What do you think about this ? Is there any reason why we couldn't do that:

    @property
    def loop(self) -> asyncio.AbstractEventLoop:
        """The event loop that the client uses for asynchronous operations."""
        if self._loop is None:
            try:
                self._loop = asyncio.get_running_loop()
            except RuntimeError as e:
                raise RuntimeError("loop is not set") from e
        return self._loop

This should also normally allow you to remove the other places where it try: excepts asyncio.get_running_loop since it would be in the property itself

[Paillat-dev]

Note, Needs testing w/ async autocompletes and typing context manager as well as ext.loop